Structural connectivity in spatial attention network: reconstruction from left hemispatial neglect.

Left hemispatial neglect (neglect) is an impaired state of spatial attention. We aimed to reconstruct structural connectivity in the spatial attention network and to identify disconnection patterns underlying neglect. We enrolled 59 right-handed patients who had their first-ever infarction in the right hemisphere and classified them into neglect group (34 patients with neglect) and control group (25 patients without neglect). The neglect group was further subcategorized into 6 subgroups based on infarcted vascular territories. Diffusion tensor imaging data were obtained from all patients. Fractional anisotropy maps were compared between neglect group/subgroups and the control group by using non-parametric voxel-based analysis, generating a lesion path mask. Probabilistic tractography analysis using the lesion path mask reconstructed the following structural connectivity in the spatial attention network, which is specifically damaged in neglect patients: (1) superior longitudinal fasciculus (SLF) I connecting the superior parietal lobule/intraparietal sulcus with the superior frontal gyrus/frontal eye field (SFG/FEF) (dorsal attention network); (2) SLF III/the arcuate fasciculus (AF) and the extreme capsule/inferior fronto-occipital fasciculus (IFOF) connecting the right inferior parietal lobule/temporoparietal junction/superior temporal gyrus (IPL/TPJ/STG) with the middle frontal gyrus/inferior frontal gyrus (ventral attention network); (3) the thalamic radiations to the spatial attention-related cortices; and (4) SLF II and IFOF interconnecting dorsal and ventral attention networks. Individual analysis indicated that isolated damage in SLF I, SLF II, SLF III/AF or the thalamic radiations to IPL/TPJ/STG due to posterior cerebral artery infarction, or simultaneous damage in four thalamic radiations due to anterior choroidal artery infarction, underlies different phenotypes of neglect.

Right hand predominant constructional apraxia due to right hemisphere infarction without corpus callosum lesions.

A 74-year-old right-handed woman without cognitive impairment suddenly developed nonfluent aphasia. Brain MRI showed acute infarction in the right frontal lobe and insula without involvement of the corpus callosum. A neurological examination demonstrated not only transcortical motor aphasia, but also ideomotor apraxia and right hand predominant constructional apraxia (CA). To date, right hand predominant CA has only been reported in patients with corpus callosum lesions. The right hand predominant CA observed in our patient may be associated with the failure to transfer information on the spatial structure from the right hemisphere to the motor cortex of the left hemisphere.

Effects of Ibuprofen and High-Voltage Electric Stimulation on Acute Edema Formation After Blunt Trauma to Limbs of Rats.

Context: Ibuprofen is widely used to manage pain and inflammation after orthopaedic trauma, but its effect on acute swelling has not been investigated. Cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold is known to curb edema formation after blunt trauma to the hind limbs of rats.Objective: To examine the effects of ibuprofen, continuous CHVPC, and simultaneous ibuprofen and CHVPC on acute edema formation after blunt trauma to the hind limbs of rats.Design: Randomized, parallel-group, repeated-measures design.Setting: Laboratory animal facility.Participants: A total of 21 3-month-old Zucker Lean rats (mass = 288 +/- 55 g) were studied.Intervention(s): We assessed the effects of ibuprofen, continuous CHVPC, and simultaneous ibuprofen and CHVPC on acute edema formation after blunt trauma to the hind limbs of rats.Main Outcome Measure(s): Limb volumes were measured immediately before and after trauma and every 30 minutes over the 4 hours of the experiment.Results: Volumes of treated limbs of all 3 experimental groups were smaller (P < .05) than those of untreated limbs, but no treatment was more effective than another.Conclusions: Ibuprofen, CHVPC, and simultaneous ibuprofen and CHVPC effectively curbed edema after blunt injury by roughly 50% relative to untreated but similarly injured control limbs of rats.